A MULTI-PROXY ANALYSIS OF DATED SEDIMENT CORES FROM NATANIS, JIM, AND TEA PONDS, FRANKLIN COUNTY, MAINE

Lacustrine sediments have the potential of containing paleoenvironmental indicators that can reflect past regional conditions. The purpose of this study is to correlate sediment records from Natanis, Jim, and Tea Ponds, each within the Dead River Watershed, Franklin County, Maine, in order to assess regional variability over the Late Holocene. Dated sediment cores were analyzed for organic matter (loss on ignition), wet and dry bulk densities, and magnetic susceptibility. Core lengths range from 1.5m to 2.5m in length, consisting entirely of gyttja with the exception of interbedded siliciclastic sands and clay layers from Natanis Pond.

Age models were created from calibrated radiocarbon dates on terrestrial macrofossils from each core and demonstrate that the core records represent between 593 ± 27 yrs BP (Natanis), 2839 ± 78 yrs BP (Jim), and 4255 ± 91 yrs BP (Tea). The age models were used to determine average sedimentation rates, showing Natanis Pond to have the highest rate of 0.25cm/yr compared to 0.08cm/yr for Jim Pond and 0.06cm/yr for Tea Pond. Higher percentages of average organic matter correspond with slower sedimentation rates, where the ponds show 14%, 37% and 40% average organic matter, respectively. Magnetic susceptibility values have an inverse relationship with organic matter, reaching a peak of 46 SI Units in Natanis Pond within the last 100 cal yrs BP.

Analyses have led to the interpretation that correlative variability between the three records represents periods of time during which the paleoenvironmental conditions were influenced by regional variables. Periods with asynchronous variability represent times of local watershed influences (i.e. land use change, etc.).